Split tail duplication into a separate pass. This is needed to avoid
running tail duplication when doing branch folding for if-conversion, and
we also want to be able to run tail duplication earlier to fix some
reg alloc problems. Move the CanFallThrough function from BranchFolding
to MachineBasicBlock so that it can be shared by TailDuplication.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89904 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LLVMTargetMachine.cpp b/lib/CodeGen/LLVMTargetMachine.cpp
index 740c950..9164f82 100644
--- a/lib/CodeGen/LLVMTargetMachine.cpp
+++ b/lib/CodeGen/LLVMTargetMachine.cpp
@@ -35,6 +35,8 @@
cl::desc("Disable Post Regalloc"));
static cl::opt<bool> DisableBranchFold("disable-branch-fold", cl::Hidden,
cl::desc("Disable branch folding"));
+static cl::opt<bool> DisableTailDuplicate("disable-tail-duplicate", cl::Hidden,
+ cl::desc("Disable tail duplication"));
static cl::opt<bool> DisableCodePlace("disable-code-place", cl::Hidden,
cl::desc("Disable code placement"));
static cl::opt<bool> DisableSSC("disable-ssc", cl::Hidden,
@@ -344,6 +346,12 @@
printAndVerify(PM, "After BranchFolding");
}
+ // Tail duplication.
+ if (OptLevel != CodeGenOpt::None && !DisableTailDuplicate) {
+ PM.add(createTailDuplicationPass());
+ printAndVerify(PM, "After TailDuplication");
+ }
+
PM.add(createGCMachineCodeAnalysisPass());
if (PrintGCInfo)